Process of manufacture of buffing elements



April 14, 1959 A. s. ROCK 2,832,139

PROCESS OF MANUFACTURE OF BUFFING ELEMENTS Filed Feb. 12, 1957 v 2Sheets-Sheet 1 April 14, 1959 A. s. ROCK PROCESS OF MANUFACTURE 0BUFFING ELEMENTS Filed Feb. 12, 1957 Z'Sheets-Sheet 2 I laavezzi'oflUnited States Patent PROCESS OF MANUFACTURE OF BUFFING ELEMENTS Albin S.Rock, East Bridgewater, Mass, assignor to F. L.

& I. C. Codman Company, Rockland, Mass., a corporation of MassachusettsApplication February 12, 1957, Serial No. 639,800

1 Claim. (Cl. 51-293) This invention relates to a process formanufacturing bufling elements. It is based on the conception that if anannulus of bufiing material of a certain type is supported by a suitabletype of metal center itself capable of being expeditiously and cheaplydismantled without damage to the annulus, then the material salvagedfrom two such annuli after they have been worn down in depth may beutilized in a further step to produce a single full-sized sectionsubstantially identical with the originals.

A well-known type of bufiing element, the so-called rufiied bufi, ismade from an effectively continuous ring comprising a strip of' biasfabric wound on itself in the form of a cylinder and comprising amultiplicity of plies. Such a ring is folded on itself along a centerline with concomitant compaction of the material adjacent that line, andusually, although in lesser degree, throughout the width of the ring toprovide two flat annuli side by side, having pleatings or rufiiingsproduced incident to its transformation in form. This duplex annulus ismounted on a supporting center of one kind or another.

Such a device is in a sense a bufling wheel and might be used alone, butsince it has a relatively narrow face, it usually in practice will bewhat is termed a section, adapted to be assembled with other sections toform a buffing wheel or cylinder having an external cylindrical workingface of comparatively great width.

Such an element wears rapidly in use. In production work a largefraction of the radial depth of the bufiing wheel is worn away in aperiod measured in hours. If the user has such a use for it, it may beshifted to another job with different demands for a further period ofuse and wear, but in general, even if so extended, its useful life isshort. It cannot be worn away right down to the center. the center in apermanent manner, whether the center is made of fiber board of variouskinds or is an expendable metal center and the section is considered asa single use or expendable device. It may have some salvage value, butthe parts are not recovered except with considerable labor and in adeteriorated condition unfitting them for new uses comparable to theold.

In accordance with the invention a bufiiing element is utilized having asheet metal supporting center, an example of which is herein shown anddescribed, the complete assembled bufling element being of such naturethat, after predetermined wear, it may be returned to the manufacturerwhere, because of its construction, it may be dismembered and at leastthe bufiing material re covered in such unimpaired condition and in suchform as to provide material for the making of a buff elementsubstantially identical with the original. The metal center may beconsidered expendable, although as will appear, salvage and reuse of atleast a part thereof may be economically practicable.

The invention will be well understood by reference The bufling materialis usually mounted on r 2,882,139 Patented Apr. 14, 19 59 2 to thefollowing drawings, showing by way of example a preferred illustrativeembodiment of the invention wherein:

Fig. 1 is a side elevation showing one face of a bufling elementincluding a center which face, merely for differentiation, is herecalled the obverse face;

Fig. 2 is a fragmentary side elevation showing the opposite or reverseface;

Fig. 3 is an enlarged section on line 3-3 of Fig. 1;

Fig. 4 is a schematic view showing an early step in the manufacture ofthe element illustrated in Fig. 3;

Fig. 5 illustrates a further stage;

Fig. 6 is a fragmentary section showing a portion of an element asshownin Fig. 3 after the butting material has been worn away for aconsiderable depth;

Fig. 7 shows the bufiing material as recovered from a worn element asshown in Fig. 6 after dismantling;

Fig. 8 shows two units as illustrated in Fig. 7, joined to provide acylindrical ring or band, ready for incorporation in a buffing elementessentially like that shown in Fig. 3; and

Fig. 9 is a fragmentary view looking radially inwardly of a portion ofthe outer periphery of the members of the center, slightly separatedaxially.

Referring now to Figs. 1, 2 and 3 of the drawings, I here show a center,denoted as a whole by the reference letter C, supporting an annulus ofbufling material denoted generally by the letter A. The center may becompared to a wheel in that it has a central portion or nave, anintermediate body portion B corresponding to the spokes (or the web of adisc wheel) and a peripheral or rim portion R which supports the annulusA which, in a way, corresponds to the non-metallic tire of a wheel. Thebuffing material A in the completed element is a generally flat annuluswith an internal radius a, an external radius b (that of the completedsection) and a depth (b-a) marked 0 on Fig. 1. In the form illustratedin Fig. 3, as it is originally made and supplied to the trade, theannulus consists of two annuli set side by side, each having a number ofplies or strata and integrally joined at the inner circumference.

Thus, in accordance with the known practices of the art, a cylindricalband or ring (like a napkin ring) may be formed of a strip of biasfabric having a width 20 wound in a multiplicity of turns to form aring. This ring is marked A(r) in Fig. 4, the letter r being suggestiveof the word ring. The ring A(r) has a radius not only greater than abut, when the buff is to be rufiied at its outer periphery,substantially greater than b. The sides of the ring are folded outwardlyalong its center line and at the same time the material is compactedcircumferentially into pleats or rufiiings so that the radius of theinner circumference of the resulting annuli is reduced to the dimensiona, and that of the outer circumference to the dimension b. Such a proceeding is not new, but it is emphasized that the material in thepresent instance is not subjected to any treatment, other than thefolding or crumpling, which would be inconsistent with its recovery,substantially undeteriorated, as hereinafter described. Thus, incontrast with many buffs, it is not impregnated with plastic orstiffening material along its inner periphery to consolidate thatportion in a solid mass, nor are fasteners used which might aflect theintegrity of the material or which could be withdrawn only atprohibitive labor cost and with probable further impairment of thatintegrity.

In contrast with such practices the annuli when brought to the formshown in Fig. 5 are mechanically held at their inner circumferences andeffectively secured by the center C, formed by separate parts which areclosed thereon in the manner of clamping jaws, but which may bedismantled readily after use, to release the annuli after they have beenworn down to a lesser radius, say one equal to one-half of dimension 0,but otherwise, except for the pleating which may readily be extended andflattened out. practically like. new.

There will next be described the preferred form of sheet metal center C,herein illustrated. It comprises two generally circular parts, obverse20 and reverse. 22. The reverse section 22 herein comprises the naveportion N with a drawn out sleeve 24 to receive in a supporting shaftthe body portion B. having openings at intervals defining between them.the spoke-like members 26, herein eight in number, which are hereinstiffened by impressed radial ribs 28. throughout their length and whichmerge into a short. cylindrical portion 30 which in cooperation withparts. of the obverse. section 20 defines theQbot tom of" an outwardlyopening channel to receive the interior circumference of. theannulus-Aof. bufling materiah, there. being an. outwardly extending flange. 32,one" of the, flanges ofthe aforesaid channel, at the outer endyof' thepart30. The flange 32 at its. outer: margin is. provided with inturnedispurs 34, preferably parallel to theaxis of rotation.

The obverse member 20 is herein open-centered and comprises a flange 36forming the opposite side of. the channel and having spurs 38 extendinginwardly therefrom, a short cylindrical portion 40 at. the inner side ofthe flange 36, from which extend ears 42v lying in a cylindrical surfaceand being adapted to pass through the openings between the spokes 26,being received against the interior of cylindrical part 30 of. thereverse member, and to have their ends bent over on the radial flange 32of the reverse member as seen in Figs. 2, 3 and'6.

In Fig. 4 the two members of the center are shown separated, positionedcentrally within the band A(r). The band A(r) is transformed into theduplex annulus as shown in Fig. 5, the interior radius of whichcorresponds substantially to the radius, a, of the bottom of the channelwhich is formed by the cooperation of the two center members as shown inFig. 5. The two members are then brought together axially tightly toembrace and clamp the annulus and are locked together by turning overthe cars 42 on the flange 32 as seen in Figs. 2 and 3. The spurs 34 and38 enter into the body of buffing material A. These spurs are out ofline in the respective twoelementsso as not to interfere with eachother. They are preferably triangular in form as seen inFig, 9v and theyareof a length to extend at least substantially to and convenientlyslightly beyond the center circumference which rufflngs however are in asense free from one another. In practice the spurs appear to find theirway into the interstices of the rufllngs without a laceration of thematerial itself, except to a negligible amount. Atthe same time, afterclamping together of the center forming members 20 and 22, the materialis firmly held in its upset or ruffled form by the clamping engagementtherewith of two gripping jaws which secure a mechanical interlock tothe annulus by means of the spurs, preventing displacement of thebufling material under the stresses occurring in use. It is pointed outthat the spurs have,v no rearwardly presented shoulders which ondismantling of the section might catch and lacerate the material, inseparating the center forming members from the buffingannuli.

The, two members ofthe center may be separated and the sectiondismantled by unbending the cars 42 and separating the two members 20and 22 axially. It would of'course be tedious to pry up the ends ofthese cars manually with a screwdriver in an individual case, but underproduction conditions" it is easy, by means Qf a suitable appliance, toexert inward or centripetal force thereon to straighten them out.

The economic advantage of the construction is availed of by thefollowing additional steps of the novel method. The bufi section asoriginally manufactured may conveniently be marked on its side toindicate a depth equal to about one-half of 0 (some allowance fortrimming is provided for in practice). When the annuli are worn down tothat mark as indicated in Fig. 6, the user retires the bull from use andreturns such. worn down sections to the manufacturer. The center isdismantled and the folded section of reduced depth withdrawn. Temporarymeans for securing the plies together during handling may be utilized.The duplex annulus as recoveredv from the worn down butt is shownseparated in Fig. 7, and is marked A2, the 2 indicating that it is in asecond stage as compared to its original state, as illustrated in Fig.-.5,, for example. The duplex annulus .of Fig. 7 hasa depthequal. toone-half of c and an. interior radius equal to a. It. may be unfoldeda'ndthe pleatings or ruflling's extendedto form a cylindrical ring of awidth 0 and a radiusv greaterv than b and equal to that of the ring A(r)in Fig. 4. Two such salvaged rings may be set side by side as seen inFig.8 and joined by an auxiliary ply or narrow band.50 as seen in Fig.8, thus providing a band with. a width 2c. and a radius greater than I),essentially equivalent to the band A(r) as diagrammed in Fig. 4. Thusthe ring shown in Fig. 8 may have the two parts at either side of itscenter line folded together, outwardly and upwardly in the figure, andthe assembly may be circumferentially compacted in the same way as theband A(r) in Fig. 4 and grasped by members 20 and 22 of a center, toprovide a new bufling element substantially duplicating that illustratedin Fig. 3. This may be worn down through half its depth. The processthen cannot be repeated because we would recover only bands having awidthv of one-fourth of c which could not be utilized in the mannershown. in Fig. 8. The user purchases and wears out two buds of a givensize and at a moderate cost, less than that of a new buff, gets anotheras good as new to wear out.

By way of precaution, to insure the integrity of the element under theconditions. of use, the sheet metal may conveniently be made a. littleheavier than that which has hitherto been used in expendable sections.Thus, by way of .example merely and without limitation, in the case. of.a section of' 14 inch diameter, sheet metal .042 inch thickhas. been.used. 1 The economy resulting from the salvage and. reuse of. a.reconstituted section equivalent to. the original. is. such, as to.permit this even the center. is.v scrapped when first removecL. However,the obverse-section 2.0 obviously is recoveredunimpaired. Thereversesection. mayrequire a closer inspection and possibly a reshaping of the.ears 42,.although the metal is such that it would stand several bendingswithout appreciable weakening. Under particular conditions of course aslight additionallabor. charge could be justified, since the parts areto be used only twice. In any instance the manufacturer will receiveback two centers for each reissued bufling element and the dismantling,justified alone by the salvage of. the valuable. buffing material, willalso at least supply him. with a marketable supply of clean segregatedscrap. Probably it would be pre ferred in any event to use. new centersfor original elements asinEig. 5, unless perhaps under emergencyconditions in time of war.

As. seeninFigs. 1 and 9 theflauge 22. of. the reverse member may haveradial corrugations 44.. The inwardly facing. crests press. into thebase of' the adjacent annulus and interlock the same. When. a. number ofsections are assembled. to form a wheel of relatively gre-atwidth offace, these corrugationsv provide exteriorly passageways to permit airentering throughout the space between the spokes 26 to pass outbetweenthe' sections and keep them cool. The" outwardly facing crests ofthe corrugaaasanse tions bear on the flat faces of the turned over ears42 of an adjacent section which ears are in such number as to occupysubstantially all the circumterence between the spokes and provide aneven bearing for the corruga tions and also serve as spacing elementscooperating therewith, slightly to increase the airway.

As seen in Fig. 9 the inward indentations of the corugations areopposite the roots of the spurs 38 and extend into the bases thereof,stiffeningthe spurs.

Certain features of the metallic center herein described are claimed inapplication Serial No. 677,053, filed August 8, 1957, that applicationbeing a continuation in part of the present application.

I am aware that the process described may be practiced by utilizingelements of physical constructions other than those described, if theyhave the general relationship and form required to permit thesubstantially unimpaired recovery of the worn down annuli of buflingmaterial, and the specific disclosure is to be considered in allrespects as illustrative and not restrictive, as is in fact clear inseveral matters from the description itself. Refer ence is to be had tothe appended claim to indicate those principles of the inventionexemplified by the particular embodiment described and which I desire tosecure by Letters Patent.

I claim:

The process which comprises detaching and spreading out into the form ofa cylindrical band the fabric from each of two used buffing sections ofknown type wherein a wide cylindrical band of plied fabric is foldedoutwardly about its center line and secured in folded position bymechanical gripping jaws clampingly engaging the same in -a radiallyshallow zone adjacent the fold line, which sections have been worn awayto approximately half their radial depth, joining one circumferentialedge of each to a circumferential edge of the other by means notsubstantially increasing the thickness adjacent the line of juncture,folding them outwardly along their line of juncture into side-by-siderelationship and securing the joined circumferential portions to asupporting center, thereby to produce a single full-sized sectioncharged throughout its circumference and to a substantial radial depthwith bufiing compound.

References Cited in the file of this patent UNITED STATES PATENTS

